You could say that, *because* it has a (non-zero) magnetic field (not vice-versa). An object is not a magnet /per se/.
Not enough.
No, that's nonsense. The best explanation that we have for that is _gravitation_. Gravitation is NOT the same as magnetism.
Terra (Earth) orbits the barycenter of the Sol System because it formed from a rotating planetary disk. That disk was rotating because it formed from the rotating part of a molecular cloud at the same time as Sol (the Sun) formed; it was what was left over from the star's formation (the star formed because that part of the cloud had cooled enough by emitting radiation, and was dense enough so that gravitation caused it to collapse on itself; the collapse caused its density to increase further, and its temperature to increase again, eventually that much that nuclear fusion became possible and likely). That piece was rotating, because small imbalances in mass (perhaps supported by a nearby supernova) cause particles of a molecular cloud to move in different directions, and when they become too close, they begin to orbit each other (or rather their common barycenter) due to gravitation.
This is not just a story or a model anymore because we can observe it in the formation of other stars and their planetary systems.
F'up2 sci.astro